Sentinel-5 is an atmospheric monitoring mission planned in the frame of the joint EC/ESA Copernicus initiative, previously known as Global Monitoring for Environment and Security (GMES). The objective of the mission, due for launch in 2021, is the operational monitoring of trace gas concentrations for atmospheric chemistry and climate applications. It will provide accurate measurements of key atmospheric constituents such as ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide, methane, formaldehyde, and aerosol properties. The space segment will be implemented as an imaging spectrometer to be flown on EUMETSAT's Metop Second Generation satellites. From a sunsynchronous LEO orbit Sentinel-5 measurements will provide a daily global coverage at an unprecedented spatial resolution of 7x7 km at nadir and will complement the Sentinel-4 GEO data over Europe. The pushbroom imaging grating spectrometer will acquire continuous spectra of Earthshine radiance covering the UV (270-370 nm), VIS (370- 500 nm), NIR (685-773 nm) and SWIR (1590-1675 nm; 2305-2385 nm) spectral regions, with spectral resolution ranging from 0.25 nm to 1 nm.

J.-L. Bézy, European Space Research and Technology Ctr. (Netherlands)B. Sierk, European Space Research and Technology Ctr. (Netherlands)J. Caron, European Space Research and Technology Ctr. (Netherlands)

B. Veihelmann, European Space Research and Technology Ctr. (Netherlands)D. Martin, European Space Research and Technology Ctr. (Netherlands)J. Langen, European Space Research and Technology Ctr. (Netherlands)